Technical Field
The present application relates generally to the field of manufacturing with novel degradable metallic materials, such as degradable alloys of aluminum, and methods of making products of degradable alloys useful in oilfield exploration, production, and testing.
Background Art
To retrieve hydrocarbons from subterranean reservoirs, wells of a few inches wide and up to several miles long are drilled, tested to measure reservoir properties, and completed with a variety of tools. In drilling, testing, and completing a well, a great variety of tools are deployed down the wellbore (downhole) for a multitude of critical applications. Many situations arise where degradable materials (e.g. materials with an ability to decompose over time) may be technically and economically desirable; for instance an element (i.e., a tool or the part of a tool) that may be needed only temporarily and would require considerable manpower for its retrieval after becoming no longer useful may be conveniently made of a degradable material. If such element is designed (formulated) to degrade within a variety of wellbore conditions after it has served its functions, time and money may be saved. A chief pre-requirement to the industrial use and oilfield use of degradable materials is their manufacturability. In contrast to plastic and polymeric materials, many among which may degrade in a wellbore environment (e.g. polylactic acid in water), metallic materials (e.g., alloys) have typically much greater mechanical strengths, and mechanical strength is necessary to produce oilfield elements that may withstand the high pressure and temperatures existing downhole.
Various degradable metallic materials have been recently disclosed by the same inventors (Marya et al.). For example, U.S. 2007/0181224 by Marya et al. discloses compositions (i.e., materials of all sort: metals, alloys, composites) comprising one or more reactive metals in a major proportion and one or more alloying products in a minor proportion. The compositions are characterized as being of high-strength and being controllably reactive and degradable under defined conditions. The compositions may contain reactive metals selected from products in columns I and II of the Periodic Table and alloying products, such as gallium (Ga), indium (In), zinc (Zn), bismuth (Bi), and aluminum (Al). Oilfield products made from these compositions may be used to temporarily separate fluids from a multitude of zones. Upon completion of their intended functions, the oilfield products may either be fully degraded, or may be forced to fall or on the contrary float to a new position without obstructing operations.
Similarly, U.S. 2008/0105438 discloses the use of high-strength, controllably reactive, and degradable materials to specifically produce oilfield whipstocks and deflectors.
U.S. 2008/0149345 discloses degradable materials, characterized as being smart, for use in a large number of downhole elements. These elements may be activated when the smart degradable materials are degraded in a downhole environment. The smart degradable materials may include alloys of calcium, magnesium, or aluminum, or composites of these materials in combination with non-metallic materials such as plastics, elastomers, and ceramics. The degradation of the smart degradable materials in fluids such as water may result in at least one response that, in turn, triggers other responses, e.g., opening or closing a device, or sensing the presence of particular water-based fluids (e.g. formation water).
Because degradable metallic materials (namely alloys) are useful for a variety of oilfield operations, methods of manufacturing oilfield products made of these degradable materials are highly desirable.